TY - JOUR
T1 - Transcriptional feedback regulation of efflux protein expression for increased tolerance to and production of n-butanol
AU - Boyarskiy, Sergey
AU - Davis López, Stephanie
AU - Kong, Niwen
AU - Tullman-Ercek, Danielle
N1 - Publisher Copyright:
© 2015 International Metabolic Engineering Society.
PY - 2016/1/1
Y1 - 2016/1/1
N2 - Microorganisms can be engineered to produce a variety of biofuels and commodity chemicals. The accumulation of these products, however, is often toxic to the cells and subsequently lowers production yields. Efflux pumps are a natural mechanism for alleviating toxicity through secretion of the product; unfortunately, pump overexpression also often inhibits growth. Tuning expression levels with inducible promoters is time-consuming and the reliance on small-molecule inducers is cost-prohibitive in industry. We design an expression regulation system utilizing a native Escherichia coli stress promoter, PgntK, to provide negative feedback to regulate transporter expression levels. We test the promoter in the context of the efflux pump AcrB and its butanol-secreting variant, AcrBv2. PgntK-driven AcrBv2 confers increased tolerance to n-butanol and increased titers of n-butanol in production. Furthermore, the system is responsive to stress from toxic overexpression of other membrane-associated proteins. Our results suggest a use for feedback regulation networks in membrane protein expression.
AB - Microorganisms can be engineered to produce a variety of biofuels and commodity chemicals. The accumulation of these products, however, is often toxic to the cells and subsequently lowers production yields. Efflux pumps are a natural mechanism for alleviating toxicity through secretion of the product; unfortunately, pump overexpression also often inhibits growth. Tuning expression levels with inducible promoters is time-consuming and the reliance on small-molecule inducers is cost-prohibitive in industry. We design an expression regulation system utilizing a native Escherichia coli stress promoter, PgntK, to provide negative feedback to regulate transporter expression levels. We test the promoter in the context of the efflux pump AcrB and its butanol-secreting variant, AcrBv2. PgntK-driven AcrBv2 confers increased tolerance to n-butanol and increased titers of n-butanol in production. Furthermore, the system is responsive to stress from toxic overexpression of other membrane-associated proteins. Our results suggest a use for feedback regulation networks in membrane protein expression.
KW - AcrB
KW - Dynamic gene regulation
KW - Membrane protein overexpression
KW - N-butanol production
UR - http://www.scopus.com/inward/record.url?scp=84952006630&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84952006630&partnerID=8YFLogxK
U2 - 10.1016/j.ymben.2015.11.005
DO - 10.1016/j.ymben.2015.11.005
M3 - Article
C2 - 26656942
AN - SCOPUS:84952006630
SN - 1096-7176
VL - 33
SP - 130
EP - 137
JO - Metabolic Engineering
JF - Metabolic Engineering
ER -